M35 Cooling System Overhaul

[HER_M35]

Hi Guys,

I serviced our M35 yesterday and discovered the top tank on the radiator has started to leak around the crimp seal, i don't think the tank's split though and will take the opportunity to do an overhaul on the cooling system with summer coming up.

My question is around the parts i'll need to do this;

Radiator - I believe that a standard V35 radiator will fit with little to no modding required, can anyone confirm this?

Thermostat - Again I've read the OEM VQ35 thermostat is the same and will run with this unless there's a better option.

Hoses - Thought i'd do the hoses (radiator, heater, etc) at the same time but i can't find any listings for these, are they the same as a V35, Z33 or is something else compatible?

Coolant - do we use the green or red coolant in our M35's? There's green in it from the compliance workshop at the moment but possibly because that's the cheapest, not the best!??!

Any advice you guys can offer would be awesome, thanks in advance,

Jas

[zei20l]

i have a 3.5L V35 radiator in mine, needed some cutting but it fit in fine. apparently the 2.5L models go straight in. a Z33 radiator will NOT fit correctly as the cap is in the wrong spot. but physically it will fit in.

VQ35 thermostat is the same, its not a big job to change, just fiddly with one of the bolt locations.

the hoses AFAIK are the same as a Z33/V35, and we use green coolant. ive been using nulon stuff in mine for ages, havent had a problem

[iamhe77]

Yup, as Iain said.

V35/G35 aftermarket radiator will fit but will need to cut the surrounds (take heed that the cap is on our drivers side of the tank)

Nismo VQ35 thermostat will serve you well

Z33/V35/G35 radiator hoses are the same as ours.

Green coolant

[HER_M35]

Thanks guys, appreciate the input.

I'll let you know how it goes, hoping to do it all this weekend.

Jas

[HER_M35]

Job complete!

Thanks again for the info guys, i ended up going with a radiator from Fenix Radiators and used the NIS1631A for $330 delivered the next day, great guys to deal with and would use them again for sure.

For those looking to do the same, a few pointers when using a V35 radiator;

This is slightly larger than stock, it's a little higher (only mm's) and wider and consequently the radiator support and the top and bottom needs to be trimmed on the passenger side only. Not hard, just a hit with a dremel and you're done

Because it's wider than stock, the fan shroud needs to be trimmed to sit flush against the radiator again, just trim off the sides where this used to wrap around the stock radiator.

The extra height means you need to trim the bottom off the two locking "mounting brackets" (it's what the G35 ,manual calls them!) so they can be locked down again (the two at the top that you twist to release the radiator).

At the bottom of the radiator where the air con condenser slots into the radiator, there are two slots that need to be dremelled slightly larger, about 1-2mm.

You may want to cable tie the bottom of the fan shroud to the radiator to keep it in place as the OEM radiator has two round holes to secure this and the replacement has two slots, again not a big deal.

Also remember to scavenge the rubber mounts (top and bottom) from the old radiator and the two captive nuts at the top of the radiator, you'll need to reuse these.

Bleeding the system was a straight forward process, follow the G35 procedure in the workshop manual and you really can't go wrong.

Hope that helps others that want to attempt this job and if anyone has any questions fell free to ask away!

Jas

[iamhe77]

no pics?

Glad it all went well.

[HER_M35]

No, no pics....... yet.

I've still got the radiator hoses coming in the mail and will try and take some of the various points that needed to be modified then.

[Daleo]

Job complete!

Thanks again for the info guys, i ended up going with a radiator from Fenix Radiators and used the NIS1631A for $330 delivered the next day, great guys to deal with and would use them again for sure.

Hope that helps others that want to attempt this job and if anyone has any questions fell free to ask away!

Jas

Nice work!

One question; the link you've provided, lists the price at $462. Where did you source the radiator from?

Cheers, Dale.

[HER_M35]

Nice work!

One question; the link you've provided, lists the price at $462. Where did you source the radiator from?

Cheers, Dale.

Fenix Radiators also have an eBay store but i called their retail store and mentioned the eBay listing just to see if they were the same company and they just did it for the eBay price, i didn't even ask for it cheaper!

[Commsman]

This seems like as good a place as any to ask my question.

I've drained the radiator & bought Nulon concentrated coolant, the one that 1L makes up to 3L etc. What's the general consensus of filling the cooling system with straight concentrate, ie not adding demineralised water? No benefit & a waste of money or good idea & works better?

Cheers, Leon.

PS - where's those install pics Jas?

[Daleo]

This seems like as good a place as any to ask my question.

I've drained the radiator & bought Nulon concentrated coolant, the one that 1L makes up to 3L etc. What's the general consensus of filling the cooling system with straight concentrate, ie not adding demineralised water? No benefit & a waste of money or good idea & works better?

Cheers, Leon.

PS - where's those install pics Jas?

Definitely don't run the concentrate straight; it's designed to be mixed with water. Glycol is nowhere near as efficient as water for heat transfer; so I always mix it at the leanest concentration; this is when it is at it's most efficient, and still able to stop corrosion & lubricate water pump seals etc.

If you spend time in snowy areas; by all means mix it stronger as recommended; but be aware; it doesn't transfer heat as efficiently. Although I don't think you'll have too much trouble with snow in Byron anytime soon Leon.

Also highly recommend using distilled or demineralised water as your make up water. Just don't drink demineralised water; it'll make you sick.

[iamhe77]

33-40% coolant and the rest demineralised water Leon.

Max would be 50/50 mix.

[PN-Mad]

Being in Byron, and having a snowflakes chance in Hell of actually reaching below 0 degrees, you can ditch the anti-freeze altogether, and use one of those fancy water wetting agents I've seen around. They reckon they work ok, and provide some benefits. I think redline or royal purple make some of them. Have a search- some race car teams use them as well. Because Racecar....

[Daleo]

Being in Byron, and having a snowflakes chance in Hell of actually reaching below 0 degrees, you can ditch the anti-freeze altogether, and use one of those fancy water wetting agents I've seen around. They reckon they work ok, and provide some benefits. I think redline or royal purple make some of them. Have a search- some race car teams use them as well. Because Racecar....

The only issue with Redline "Water Wetter" and most of the others; is that they require regular topping up; more often than Glycol based coolants.

I've used the Redline one on a marginal cooling; it wasn't that impressive; certainly nothing like the 10 odd degrees they claim.

[PN-Mad]

Why do they require topping up? Do they evaporate, when Glycol has some anti-evaporative properties?

Thats interesting.

I'll be receiving a Radiator soon, and a Nismo Thermostat. Hope to keep my temps down a bit.

Edit. Just actually used my brain , whenever you drop coolant on the garage floor, shit takes forever to evaporate, so I guess I answered my own question.

Edited April 18, 2012 by PN-Mad

[Commsman]

Thanks guys; consensus is mix as recommended (or a little less) for best cooling performance.

Never heard of demineralised water making you sick if you drink it, but did a quick search & sure enough the W.H.O agrees. Will drink the green Nulon stuff instead.

[iamhe77]

Yeah, among other things demineralized water will absorb minerals from your body and then wash them out when you whizz. Not ideal lol.

Nulon coolant with it's magical green ingredient should fill all your dietary requirements

[Deep Dish V35]

i bought the same radiator from a US ebay seller called RWIAMERICA, including postage it was still $100 cheaper than anything i could find in australia

[scotty nm35]

I just bought one of these after seeing the quality first hand. I damaged my Mishimoto unfortunately so i'm going back to the stock setup for a while.

http://www.ebay.com.au/itm/190638505278?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649#ht_1906wt_1159

[ironpaw]

I just bought one of these after seeing the quality first hand. I damaged my Mishimoto unfortunately so i'm going back to the stock setup for a while.

How'd you do that?